Research and Application of Multi-Technology of Air Underbalanced Geothermal Drilling

Abstract

The underbalanced drilling technology is applied to geothermal Wells with high rate of penetration and reservoir protection. After nearly 10 years of continuous research on the underbalanced drilling technology in deep geothermal wells, the author team summarizes a series of empirical parameters, practices, and measures which are of promoting significance to the development of the industry. This paper will comprehensively introduce the air pressure, air displacement, weight on bit, revolution per minute(rpm), and other drilling parameters applicable to the deep well underbalanced drilling process to guide the air compression equipment and bit selection; Then, elaborate the scheme to deal with large water inflow and formation collapse. Further, disclose the reasonable design of a well structure, correct handling of abnormal conditions, and avoid downhole accidents. Through the publication of this paper, it is expected to lead and drive the application of underbalanced drilling technology in deep Wells.